Beginning with the industrial revolution and continuing to the present, mechanized equipment has allowed workers to produce goods with greater speed and less effort than possible with manually-powered tools. Unfortunately, the power and high operating speeds of mechanized equipment creates a risk for those operating such machinery. Each year thousands of people are maimed or killed by accidents involving power equipment.
As might be expected, many systems have been developed to minimize the risk of injury when using power equipment. Probably the most common safety feature is a guard that physically blocks an operator from making contact with dangerous components of machinery, such as belts, shafts or blades. In many cases, guards are effective to reduce the risk of injury, however, there are many instances where the nature of the operations to be performed precludes using a guard that completely blocks access to hazardous machine parts.
A new safety system has been developed to detect when a person accidentally contacts a dangerous portion of a machine. The system then reacts to minimize any injury from that contact. The system, when implemented on a table saw, for example, may detect accidental contact between a person and the blade of the saw, and then react by stopping and/or retracting the blade to minimize injury. However, the new safety system does not disclose a way for a person to touch a part of the machine to test whether the safety system is working to detect accidental contact, or to test whether the safety system would perceive a given material, such as green wood, as a person. This application discloses a safety system to detect accidental contact between a person and a dangerous portion of a machine, and further discloses a test mode to allow a person to test whether the new safety system is operating to detect the accidental contact, and to test whether the new safety system perceives various materials as a person.